JP2014126426A - Method for manufacturing measurement equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing measurement equipment which can be more easily manufactured.SOLUTION: Three or more spacers 8 are arranged at each predetermined interval between the outer periphery of a glass panel 5 and the inner peripheral surface of a cover 3. Since the glass panel 5 and the cover 3 are arranged at non-contact positions, it is possible to easily perform the positioning of the glass panel 5. Thus, it is possible to more easily manufacture measurement equipment.

Description

  The present invention relates to a method for manufacturing a measuring device, and more particularly to a method for manufacturing a measuring device including a lid member to which a glass panel is attached.

  Conventionally, measuring instruments installed in factories and offices that handle flammable gases and flammable liquids, such as differential pressure transmitters, gauge pressure sensors, and absolute pressure sensors, must have an explosion-proof structure. Has been. This explosion-proof structure is also required for a display unit that displays measurement results. An example of this is shown in FIG.

  FIG. 4 shows a lid member 100 that is attached to a main body having a display element and a sensor such as an LCD (Liquid Crystal Display), and that allows the display of the display element to be visually recognized from the outside and hermetically seals the main body. . The lid member 100 is formed in a cylindrical shape, and a cover 110 whose one end 101 is attached to the main body, a disk-shaped glass panel 120 attached to an opening on the other end 102 side of the cover 110, and the other end of the glass panel 120 And a spring 130 for biasing toward the 102 side.

  Here, a potting material 140 is filled between the inner peripheral surface of the cover 110 and the glass panel 120 (see, for example, Patent Document 1). As a result, the inside and the outside of the cover 110 are isolated from each other, which satisfies the requirements for the explosion-proof structure.

JP 2005-195909 A

  However, when the potting material 140 is filled, if the potting material is filled in a state where the cover 110 and the glass panel 120 are in contact with each other, an electric spark or heat leaks to the outside from a contact portion where the potting material does not enter. There is a fear. For this reason, when filling the potting material 140, it is necessary to accurately align the glass panel 120 so that the glass panel 120 does not come into contact with the inner peripheral surface of the cover 110. However, this operation is very troublesome.

  Then, an object of this invention is to provide the manufacturing method of the measuring device which can be manufactured more easily.

  In order to solve the above-described problems, a manufacturing method according to the present invention includes a main body and a cylindrical cover in which one end is attached to the main body and a convex portion protruding toward the axis is formed at the other end. A method of manufacturing a measuring instrument including a lid member, wherein a panel placement step of placing a plate-like glass panel on a surface on one end side of a convex portion, between the outer periphery of the glass panel and the inner peripheral surface of the cover A spacer placing step for placing three or more spacers at predetermined intervals, and a filling step for filling a potting material between the outer periphery of the glass panel on which the spacers are placed and the inner peripheral surface of the cover. It is what.

  The manufacturing method may further include a mounting step of mounting an O-ring in an annular concave portion formed on a surface on one end side of the convex portion before the panel placing step.

  Moreover, in the said manufacturing method, you may make it further have a biasing member arrangement | positioning step which arrange | positions the biasing member which presses a glass panel to the other end side of a cover after a filling step.

  In the manufacturing method, the spacer may be made of the same material as the potting material.

  According to the present invention, since three or more spacers are arranged at predetermined intervals between the outer periphery of the glass panel and the inner peripheral surface of the cover, the glass panel is arranged at a position where the cover does not come into contact. The alignment of the glass panel becomes easy, and as a result, the measuring instrument can be manufactured more easily.

FIG. 1 is a cross-sectional view schematically showing a configuration of a measuring instrument according to an embodiment of the present invention. FIG. 2 is a flowchart showing a method for manufacturing a measuring instrument according to the embodiment of the present invention. FIG. 3A is a top view and cross-sectional view for explaining a method for manufacturing a measuring instrument according to an embodiment of the present invention. FIG. 3B is a top view and a cross-sectional view for explaining the manufacturing method of the measuring instrument according to the embodiment of the present invention. FIG. 3C is a top view and a cross-sectional view for explaining the method for manufacturing the measuring instrument according to the embodiment of the present invention. FIG. 3D is a top view and a cross-sectional view for explaining the method for manufacturing the measuring instrument according to the embodiment of the present invention. FIG. 3E is a top view and a cross-sectional view for explaining the manufacturing method of the measuring instrument according to the embodiment of the present invention. FIG. 3F is a top view and a cross-sectional view for explaining the method for manufacturing the measuring instrument according to the embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing a configuration of a conventional measuring instrument.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Configuration of measuring equipment]
As shown in FIG. 1, a measuring instrument according to the present embodiment includes a main body 1 including a display element such as an LCD (Liquid Crystal Display), a sensor element, and the like, and is attached to the main body 1 to display the display element. A lid member 2 that is visible from the outside and hermetically seals the main body is provided.

  The lid member 2 has a cylindrical cover 3 provided with a convex portion 31 projecting toward the axis at one end, and an O disposed on the other end side surface (hereinafter referred to as “upper surface”) of the convex portion 31. Ring 4, glass panel 5 disposed in convex cover 3, potting layer 6 filled between cover 3 and glass panel 5, and glass panel 7 toward one end of cover 3 And an urging spring member 7.

The cover 3 is formed in a cylindrical shape, and at one end, a disc-shaped convex portion 31 is formed that protrudes in the direction perpendicular to the axis and toward the axis, and has a circular opening at the center. Yes. An annular recess 32 is formed on a surface on the other end side of the protrusion 31 (hereinafter referred to as “upper surface”). Further, an engaging portion 33 that is recessed toward the outer peripheral surface is formed on the inner peripheral surface of the substantially central portion in the axial direction of the cover 3. Further, a screw groove (not shown) for screwing with the main body 1 is formed on the outer peripheral surface on the other end side of the cover 3.
Such a cover 3 is comprised from metals, such as stainless steel, for example.

  The O-ring 4 is made of a metal annular member.

  The glass panel 5 is formed in a disc shape whose outer diameter is smaller than the inner diameter of the cover 3. Such a glass panel 5 is comprised from the tempered glass, for example.

  The potting layer 6 is made of a known potting material such as silicon.

  The spring member 7 is formed of an annular leaf spring whose outer diameter is slightly larger than the inner diameter of the cover 3.

[Manufacturing method of measuring equipment]
Next, a method for manufacturing a measuring instrument according to the present embodiment will be described with reference to FIG.

First, as a preparation, the potting material is degassed in order to remove bubbles contained in the potting material (step S1). In the present embodiment, silicon is used as the potting material. Deaeration can be performed, for example, by placing a potting material in the vacuum chamber and evacuating the vacuum chamber with a vacuum pump.
Moreover, the degreasing process which removes an oil component from the surface of each component of the measuring device containing the cover 3 shown to FIG. 3A is performed (step S2).

  Next, as shown in FIG. 3B, the O-ring 4 is attached to the concave portion 32 formed on the upper surface of the convex portion 31. Then, as shown in FIG. 3C, the glass panel 5 is placed on the upper surface of the convex portion 31 in which the O-ring 4 is attached to the concave portion 32 (step S4). As a result, the O-ring 4 is pressed and crushed by the cover 3, and is in close contact with the cover 3 and the glass panel 5. Thereby, since the cover 3 and the glass panel 5 are isolated by the O-ring 4, the airtightness between them can be improved.

Next, as shown in FIG. 3D, the spacer 8 is disposed between the peripheral surface of the glass panel 5 placed on the upper surface of the convex portion 31 and the inner peripheral surface of the cover 3 facing this peripheral surface ( Step S5).
Here, the spacer 8 is made of the same material as the potting material degassed in step S <b> 1, and is formed in a spherical shape having a diameter approximately half the difference between the inner diameter of the cover 3 and the diameter of the glass panel 5. Such a spacer 8 can be produced, for example, by putting the material of the spacer 8 into a mold and solidifying it.
The spacer 8 is arranged by, for example, the user inserting the spacer 8 into the gap between the glass panel 5 and the cover 3 using tweezers or the like. In the present embodiment, three spacers 8 are arranged at equal intervals. Thereby, the inner peripheral surface of the cover 3 and the peripheral surface of the glass panel 5 are in a state of being spaced apart at equal intervals. Thus, in this Embodiment, the cover 3 and the glass panel 5 can be correctly aligned by the simple operation | work which arrange | positions the spacer 8. FIG.

Next, as shown in FIG. 3E, the potting material deaerated in step S1 is filled between the inner peripheral surface of the cover 3 on which the spacer 8 is disposed and the peripheral surface of the glass panel 5 (step S6).
At this time, since the spacer 8 is inserted, the gap between the inner peripheral surface of the cover 3 and the peripheral surface of the glass panel 5 is equal, and the cover 3 and the glass panel 5 are not in contact with each other. As a result, the potting material reaches the gap between the cover 3 and the glass panel 5. Therefore, after the potting material is cured, the potting layer 6 is uniformly formed between the inner peripheral surface of the cover 3 and the peripheral surface of the glass panel 5.

  In the present embodiment, since the spacer 8 and the potting material are made of the same material, the potting material is cured integrally with the spacer 8, so that high sealing performance can be realized.

  When the potting material is filled, the cover 3 is evacuated so that there is no unfilled portion of the potting material (step S7). This evacuation is performed by evacuating the vacuum chamber containing the cover 3 with a vacuum pump, as in the case where the potting material is degassed in step S1. Here, evacuation for 5 minutes or more and release to the atmosphere are repeated twice or more. Thereby, an unfilled part can be eliminated.

  When vacuuming is performed, the potting material adhering to the glass panel 5 is wiped off (step S8), and then vacuuming is performed for 1 hour (step S9). Further, after fixing the glass panel 5 while being pressed toward the cover 3 (step S10), after vacuuming for 1 hour (step S11), it is confirmed whether or not bubbles exist in the potting material ( Step S12).

  When bubbles exist in the potting material (step S12: NO), the potting material is reinjected (step S20), and the process returns to step S10.

  On the other hand, when there is no bubble in the potting material (step S12: YES), the potting material is heated and cured (step S13). Thereby, the potting layer 6 is formed. The potting material can be cured by, for example, putting the cover 3 filled with the potting material into a heating furnace and heating it.

  When the potting layer 6 is formed, the state of the potting layer 6 is confirmed (step S14). This is confirmed by visual observation by the user as to whether the potting material is hardened, air bubbles are not present, or the potting material is not peeled off.

  When the state of the potting layer 6 is confirmed, after the lubricant is sprayed on the spring member 7 (step S15), the spring member 7 is assembled to the cover 3 as shown in FIG. 3F (step S16). The spring member 7 is assembled by inserting the spring member 7 into the cover 3 from the other end side of the cover 3, and then fitting the edge of the spring member 7 into the engaging portion 33. It is carried out by setting it to the state which protruded. As a result, the spring member 7 presses the glass panel 5 at the one end side of the cover 3, so that the glass panel 5 is fixed inside the cover 3.

  When the spring member 7 is assembled, it is confirmed whether or not the spring member 7 is assembled in an appropriate state (step S17). This confirmation is performed, for example, by visual observation by the user.

  When the spring member 7 is not assembled in an appropriate state (step S17: NO), the user corrects the assembled state of the spring member 7 (step S21).

  When the spring member 7 is assembled in an appropriate state (step S <b> 17: YES), or when the state in which the spring member 7 is assembled is corrected, the user performs final confirmation on the lid member 2. Thereby, the cover member 2 will be assembled.

  As described above, according to the present embodiment, three or more spacers 8 are arranged at predetermined intervals between the outer periphery of the glass panel 5 and the inner peripheral surface of the cover 3. Since it arrange | positions in the position which does not contact with the cover 3, the alignment of the glass panel 5 becomes easy, As a result, a measuring instrument can be manufactured more easily.

In this embodiment, the case where the potting material deaerated in step S1 is used as the material of the spacer 8 has been described as an example. However, the material of the spacer 8 is not limited to this, and various materials can be used freely as appropriate. Can do.
In the present embodiment, the case where three spacers 8 are provided has been described as an example. However, the number of spacers 8 is not limited to this, and can be set as appropriate as long as it is three or more.

  The present invention can be applied to various devices for assembling a glass panel, such as a sensor device and a camera.

  DESCRIPTION OF SYMBOLS 1 ... Main body, 2 ... Cover member, 3 ... Cover, 4 ... O-ring, 5 ... Glass panel, 6 ... Potting layer, 7 ... Spring member, 31 ... Convex part, 32 ... Concave part, 33 ... Engagement part.

Claims (4)

A method of manufacturing a measuring instrument comprising a main body and a lid member having one end attached to the main body and a cylindrical cover formed with a convex portion protruding toward the axis at the other end,
A panel placement step of placing a plate-like glass panel on the one end surface of the convex portion;
A spacer arrangement step of arranging three or more spacers at predetermined intervals between the outer periphery of the glass panel and the inner peripheral surface of the cover;
A filling step of filling the potting material between an outer periphery of the glass panel on which the spacer is disposed and an inner peripheral surface of the cover. In the manufacturing method of the measuring device according to claim 1,
A method for manufacturing a measuring instrument, further comprising: an attaching step of attaching an O-ring to an annular concave portion formed on the surface of the one end side of the convex portion before the panel placing step. In the manufacturing method of the measuring device according to claim 1 or 2,
After the filling step, there is further provided an urging member disposing step of disposing an urging member that presses the glass panel against the other end side of the cover. In the manufacturing method of the measuring device according to any one of claims 1 to 3,
The said spacer is comprised from the same material as the said potting material. The manufacturing method of the measuring device characterized by the above-mentioned.

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